Now, I had a male that lived in one of those before. He had no aeration, but I put a little heater in there. And he got 50% water change at least everyday. if not a full 100% when I got wiser abit later. Anyhow, I had moved Blaze into a 5 gallon, with a heater, some aeration. and he FLIPPED. moved him back into his little home like this, happy as could be. blew bubbles all the time, ate better, and was active. But I do agree, as a rule these are not good unless you change the water daily, it's a bad thing for your fish. And to divide it, is bad.